Device for replacing springs

ABSTRACT

A device useful in replacing springs in equipment such as chain saws, lawnmowers and the like having pull-rope starter assemblies is provided which device comprises a substantially cylindrical or similar member about which the old or new spring is wound and movably positioned on said member a collar capable of being moved into contact with and held against the wrapped spring to hold it in place while it is being moved to and inserted into the equipment. The surfaces of the element against which the spring is wound are substantially smooth to afford a ready sliding of the wound spring off the device into the operative position in said equipment.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of my application Ser. No. 724,289,filed on Sept. 20, 1976 now abandoned.

PRIOR ART

Basically, the replacement of springs in lawnmowers, chain saws andsimilar equipment is done by hand. The repairer holds the outer end ofthe spring and tightly winds the spring, preventing uncoiling with hishands and fingers. With the wraps of the spring aligned so that the coilis uniform in height, the worker inserts the coil in the housing, andhooks the outer end in a slot or about a pin or the projection or slotin the housing as provided. With the outer end hooked in place, therepairer arbors the other end--that is, he secures it in a bar, shaft,spindle or about a pin or the like that is part of the starter. Theassembly is then ready.

It is easily understood that this hand winding operation not only takestime but can involve mishaps. The tendency of the spring to unwindeither longitudinally or to jump out of place vertically is ever presentand the clearances in the housing are so slight that the worker must beever alert and efficient. Pinched, scuffed and cut fingers and handsmake the operation a frustrating one. While certain devices, as in U.S.Pat. Nos. 3,748,716 and 3,802,300 have been devised, there is need for asimple, inexpensive apparatus that allows one to do the job quicklywithout mishap.

Thus, an object of this invention is the provision of an apparatus whichis simple, easily operated and effective in replacing springs in starterassemblies.

Another aim is the provision of a device having a small number of partsone of which affords the winding of the spring thereon and another ofwhich affords holding it in place.

A still further purpose is providing a device which affords a ready,efficient means for replacing a spring in a starter assembly yet whichhas parts that are, in effect, independently movable as to each other.These and other objectives appear hereinafter.

SUMMARY OF THE INVENTION

The objects of this invention are accomplished, in one embodiment, bythe provision of a hollow, cylindrical body having a height of about 2to 5 inches and an inside diameter of about 1.0 inch to about 2.5 inchesbeing slightly larger than the diameter of the arbor around which thespring is to be positioned. Usually the inside diameter is preferably1.25 inches. At least one slot is cut into the wall of cylinder at oneend, the cut being parallel to the long axis of the cylinder and havinga width slightly greater than the thickness of the spring so that thebent or hooked end of the spring can readily be inserted therein to holdthe spring during working. A flat, notched disk is provided which has ahole in its center part, the diameter of which is slightly greater thanthe outside diameter of the cylinder. The disk and the cylinder co-actbut are not fixed to each other, so that they are readily separated andso that the disk may be moved up and down about the cylinder with ease.

The user winds the spring on the cylinder and using the disk to hold itin place he carries the apparatus with the spring on it about from placeto place and easily and smoothly inserts the spring into the housing.The operation is smoothly done with minimum wear and tear of the user'sfingers and hands. Since the two parts are so simple and sturdy and nogears, clutches or the like are involved, the apparatus has a long lifeat a low cost.

In certain equipment the clearances are greater because of the placementof clutch or other starter parts in top portions that are positionedafter the replacement of the spring. For such devices, the cylinder canbe replaced by a solid element about which the spring can be wound, theaforesaid slot or an equivalent thereof being present. Such a circularsolid rod can be partly hollowed out at the winding end, if desired. Inanother embodiment, the apparatus comprises two concentric wires orbands held together by a radial wire or band or a plurality can be used,the outer wire or band affording the surfaces against which the springis wound.

The invention will be further understood by reference to the drawings,which are given with reference to the cylindrical embodiment and givenfor illustration purposes only and of which

FIG. 1 is a front elevation of the apparatus of this invention without aspring wound thereon;

FIG. 2 is a top plan view of the disk;

FIG. 3 is a bottom plan view of the assembly with a spring wound thereonand with repairer holding all in place, the spring being shown inphantom about the spool; and

FIG. 4 is a rear elevational view with the spring being held in place,the view being partially broken away.

DETAILED DESCRIPTION OF THE INVENTION

As can be seen in FIG. 1 the apparatus 10 of this invention comprises ahollow spool or cylinder 11 having at least one slot 12 therein andassociated with it disk 13 having slots 14. The slots 14 are better seenin FIG. 2, a top plan view, which shows notch 12 in form of displaced orcrimped end walls 15 of the notch. Such displaced walls in cut 12 arenot essential, since the spring 16 (FIG. 4) normally has a hook end 17that fits snugly into the slot, as shown in FIG. 4, holding the springin place.

As can also be seen in FIG. 4, the height of cylinder 11 is such thatthe cupped hand of the worker can virtually contain most of theapparatus. Thus, the cylinder is usually about 2 to 5 inches in height.Greater heights can be used, since the user can surround the spool withhis hand, in the manner of holding a drinking glass, and yet activateslots 13 with his fingers. However, such heights are not needed and aspool of about 3 inches in height is usually adequate and preferred. Thethickness of the walls of the cylinder is immaterial just so the insidediameter is sufficient to clear most spindles or the like contained instarter assemblies. The spool may be constructed of metal, wood orplastic materials or of any similar sturdy material.

The disk 13 can be made of such materials. Generally, for ease ofconstruction and for visability the disk is made of a transparentplastic material as, for example, a polyformaldehyde, a polyacrylate, apolyamide and the like. The center hole 24 has a diameter just slightlylarger than the OD of the spool, so that the disk can be moved up anddown the cylinder with ease yet is not subject to tilting or wobbling. Aplurality of notches 14 are conveniently, usually symmetrically, formedon disk 13, although one would be sufficient. Such a notch, or notches,affords a place for the thumb or finger of the user and allows him tokeep the wound spring in place.

In use, the operator places the hooked inner end 18 of the spring 16into slot 14, as shown in FIGS. 3 and 4. Then, while holding the otherend 19 (FIG. 3) of the spring with the other hand, he rotates spool 11,usually with its bottom edges on a flat surface such as 20 in FIG. 4.Disk 13 is about spool 11 and during the rotation it is, of course,above spring 16, and can intermittently be brought to bear against thetop edges of spring 16. Thus, a very tight and even winding is effected.With that done, the user pushes disk 13 down on the top edges of spring16 usually with his hand cupped as shown in FIG. 4 and with his fingers,like 21 and 22, in appropriate notches and with the tips of the fingersbearing against spring 16 at their respective places. A disk free ofnotches, such as shown in FIG. 2 by dotted lines 23 to indicate theabsence of notches 14, can be used, though such requires the user toextend his fingers over the edges of disk 13 and then inwardly tocontact spring 16. Use of the unnotched disk also leads to lessclearance for the user's fingers as he inserts the disk into the motorhousing (not shown).

With the disk 13 pressing against spring 16 wound on spool 11 the usercan pick the entirety up and move it around, turning it upside down, asin FIG. 3, if he wishes. The combination of the pressure of disk 13 onthe spring 16 and the pressure of the fingers against the spring keepsthe spring in place as it is moved from the flat surface 20 to the motorhousing. There the user aligns the slot or retaining unit in the starterassembly that is to receive hooked end 17 with that end, and then, withthe alignment effected, he merely pushes gently down on disk 13 whileeasing up the pressure exerted by his fingers. As a result the springslips readily into place. The other end of the spring, end 19 (FIG. 3),is held and fixed into position as the last step.

The apparatus of this invention utilizes two uncomplicated parts thatrequire no moving linkages between them in their use. They co-act simplyand effectively. Both ends of the spring to be inserted are positionedwith ease even though the spring is tightly wound. The disadvantages ofhand winding and insertion without the use of tools are avoided, andtroublesome, moving parts of complicated devices are not needed.

While the invention has been disclosed herein in connection with certainembodiments and certain structural and procedural details, it is clearthat changes, modifications or equivalents can be used by those skilledin the art; accordingly, such changes within the principle of theinvention are intended to be included within the scope of the claimsbelow.

I claim:
 1. Apparatus for use by a person in replacing a spring in adevice, such as a chain saw, which apparatus comprises a cylindricalbody which is hollow at one end which has an inside diameter larger thanthe arbor around which said spring is to be positioned;at said end ofsaid cylindrical body, anchor means to hold one end of said spring inplace during the winding of said spring around the outer walls of saidbody at said end, said wall being substantially smooth to afford readysliding of the wound spring off said body when said end of said body andsaid wound spring are positioned for placement of said spring about saidarbor; and an element slidable on said cylindrical body which elementcomprises a ring-like element having an inside diameter slightly largerthan the outside diameter of said cylindrical body and being freelymovable to bring it into and out of operative contact with a springwound around said outer walls of said body at its said end and when inoperative contact with said spring being capable of being readily heldby a hand of the user while the resultant assembly is brought intoreplacement position of said spring about said arbor in said device,said slidable element comprising a disk the majority of which fullycovers the spring coil wound on said body but having indentations whichpermit fingers of said person to contact the sides of the coil toprevent it from unwinding as said person moves the coil into positionfor replacement.
 2. Apparatus in accordance with claim 1 in which saiddisk is made of a plastic material.
 3. Apparatus in accordance withclaim 1 in which said disk is flat.
 4. Apparatus in accordance withclaim 1 in which said disk is transparent.